robertson



April 8, 1930. w. H. ROBERTSON v1,753,479

ELASTIC DRIVE FOR CASH REGISTERS I Filed Oct. 30, 1925 4 Sheets-Sheet 1 FIG. 1

William H. Robertson April 8, 1930. w. H. ROBERTSON 1,

ELASTIC DRIVE FOR CASH REGISTERS Filed Oct 50, 1925 4 Sheets-Sheet 2 mnmtdz William Robertwn attain/M 4.

April 1930. w. H. RKOBERTSON 1,753,479

ELASTIC DRIVE FOR CASH REGISTERS Filed 001;. 50, 1925 4 Sheets-Sheet 3 William H. Robertson B, M 6

April 1930. w. H. ROBERTSON 1,753,479

ELASTIC DRIVE FOR CASH REGISTERS Filed Oct. 50-, 1925 4 Sheets-Sheet ,4

gwuc mtoz William H. ome

Patented Apr. 8 1930 UNITED STATES PATENT OFFICE;

WILLIAM H. ROBERTSON, OF DAYTON,OI IIO ASSIGNOR, BY MESNE' ASSIGNMENTS, TO

THE NATIONAL CASH REGISTER, MARYLAN ELASTIC DRIVE FOR CASH REGISTERS Application filed October 30, 1925. Serial No. 65,828.

This invention relates to improvements in motor drive mechanism for calculating machines and the like, and is shown herein, by way of illustration, attached to a cash reg ister of theht pe shown in Letters Patent of the United States, No. 1,242,170, issued to F. L. Fuller, October 9, 1917.

One object of this invention is to provide a means for automatically rendering the driving clutch ineffective, and for cutting off the current through the driving motor, when the machine is suddenly stopped by an interference in the mechanism, or because of improper operation, thereby relieving the strain on, and preventing the shearing of, some of the parts. The driving clutch automatically becomes effective again when the machine is brought home after the interference has been removed.

Another object is to provide a meansfor cushioning the momentum of the driving mechanism when the load of the machine is increased during various stages of a cycle of operation. 1

Another object is to provide a means for enabling the operator or repairman to determine the exact time during the cycle of operation at which the machine was stopped.

With these and incidental objects in View, the invention includes certain novel features of construction and combination of parts, the essential elements of which are set forth in appended claims and a preferred form or embodiment of which is hereinafter described with reference to, the drawings which accompany and form part of this specification.

Of said drawings:

Fig. lis a left side view of the machine to illustrate the driving motor, showing the mechanism for cutting off the current through the driving motor.

Fig. 2 is an enlarged detail view of the control switch, showing the mechanism in the position it assumes when the switch has been opened by the machine.

Fig. 3 is a side View of the releasing mechanism of the machine.

Fig. 4 is a detail view of part of the driving clutch.

order to overcome these and other Fig. 5 is a detail View, of the resilient coupling means interposed between the main operating shaft and the motor.

Fig. 6 is an end elevation, partly in section, of the mechanisms shown in'Figs. 4 and 5.

Fig. 7 is a detail View showing the control switch in closed position during an operation of the machine. a

Fig. 8 is a plan View showing the control switch and the driving clutch.

Fig. 9 is a detail view of the controlswitch and its cooperating mechanism in open position.

Fig. 10 is a detail view of part of a latch mechanism cooperating with the control switch.

Fig. 11 is adetail viewof the release shaft and the mechanism for restoring the release shaft to its'vnormal position.

Fig. 12 is a detail of the mechanism for releasing the release shaft.

Fig. 13 is a detail view of the mechanism for restoring the release trip arm to its normal position.

. [a general The mechanism hereinafter set forth is adapted for use with calculating machines or other intermittently operated mechanisms. It is herein shown adapted to be used in connection with a cash register of the type illustrated and described in the above mentioned patent. In complicated machines of this type interferences may sometimes occur which bring the machine to a sudden stop. Sometimes the same result occurs because of improper operation of the machine. Under such adverse conditions the momentum of the driving motor is apt to cause either shearing or straining of some of the parts, thereby making it necessary to tear down the whole machineand replace the damaged parts. In

disadvantages in the prior machines, the present invention includes a mechanism whereby the main operating shaft is driven through a resilient means. l'Vhen the main operating shaft is suddenly stopped, this resilient means continues its travel for a slight distance to avoidplacing undue strain on the operating. continued advance of the shaft, and such COMPANY, OF DAYTON, OHIO, A. CORPORATION OF partly broken away,

resilient means is utilized to control certain parts whereby the driving clutch is disengaged and the switch for completing the motor circuit is opened, thereby cutting off the supply of power to the motor.

An index is provided on the main shaft of the machine in order to enable the operator or the mechanic to determine the exact time at which the machine was stopped.

" In detail The machine herein selected to illustrate this invention, is driven by an electric motor 80 (Fig. 1) of conventional design, mounted on a suitable base adjacent the left side frame 99 of the machine the motor having the usual field coil 101 and armature 102 including a commutator 73, brushes 74 and shaft 85. A worm 86 (Figs. 6 and 9) fast on the armature shaft 85 of the motor, or an extension thereof, meshes with a worm wheel 87 journaled on the hub of a clutch shell 88 secured on a drive shaft 89 journaled. at its opposite ends in bearings on the side frame 99 and in a bracket 127 (Fig. 1), respectively.

The shell or drive member 88 of the clutch encircles a driven clutch member or disk 46 (Fig. 6) fast on the inner reduced end of the hub 71 of a drive pinion 112 journaled on the drive shaft 89.

The driven clutch disk 46 is peripherally recessed, as shown in Fig. 4, each recess adapted to accommodate a hollow roller 110 loosely encircling a locating pin 104 projecting into the recess from the side of a clutch release disk 42 journaled on the hub of a tensioning cam disk 41 also fast on the reduced end of the hub 71 of the drive pinion 112, the clutch release disk 42 being located between the driven disk 46 of the clutch and the tensioning cam disk 41.

The bottom walls 111 of the recesses in the driven clutch disk 46 are inclined, the rollers 110 resting on these walls, and spring-pressed thrust pins 103 slidingly seated in the abrupt side walls at the lower ends of the recesses,

tend to force the loosely mounted rollers 110 counter-clockwise, as viewed in Fig. 4, to the highest points on the inclined bottom walls 111.

A stud 43 (Figs. 3 and 6) extends laterally from the. outer face of the tensioning cam disk 41 and protrudes through an arcuate slot (see dotted lines Fig. 3) formed in a switch-controlling cam disk 38 journaied adjacent the tensioning disk 41, on an intermediate section of the hub 71 of the drive pinion 112. One end of a spring 44 coiled about the hub of the switch controlling disk 38 is fast to a post 45 (Fig. 3) projecting from the control disk, the opposite end of the spring being anchored to the protruding stud 43 of the ten sioning cam disk 41. This spring 44, operating-on the stud 45, tends to rock the switchcontrolling cam disk 38 counter-clockwise in Fig. 3, but is normally held from so doing by the forked head of a detent 36 (Fig. 3) pivoted at 34 to the side frame 99 of the ma chine, which forked head normally lies in the paths of a shoulder 40 (Figs. 4 and on the periphery'of clutch release disk 42, and of a shoulder 39 (Figs. 3 and 6) on the tensioning cam disk 41, and of an abutment 37 (dotted lines, Fig. 3) fast on the switch controlling cam disk 38 to hold the clutch members 88 and 46 disconnected, and the spring 44 under tension with the spring post 45 adjacent the tensioning stud 43, as shown in Fig. 3, and as more fully explained in the U. S. patent to Kettering and Chryst, No. 1,144,418, June 29,1915. A spring 35 (Fig. 3) tends to rock the clutch detent 36 to its inefiective position, but is normally prevented from so doing by a restraining arm 31 fast on a release shaft 30, the restraining arm lying in the path of a stud 32 or other projection on the free end of an arm 33 connected to the clutch detent 36, as shown in Fig. 2 of U. S. Letters Patent to Bernis M. Shipley, No. 1,619,796, March 1, 1927.

The clutch detent 36, by its engagement with the shoulder 40 of the clutch release disk 42, retains the latter with its pins 104 stationary and the slight additional advance permitted the driven clutch disk 46 and its tensioning cam disk 41 together with the rollers 110, on the preceding operation, causes the driven cam disk 46 to bring the deeper portions of its peripheral recesses beneath the clutch rollers 110 and at substantially the same time the clutch rollers strike the pins 104 and release themselvesfrom the inner periphery of the flange of the drive clutch member 88 to disconnect the clutch members. During such disconnecting operation, the advance of the driven clutch disk 46 crowds the spring-pressed plungers 103 against the arrested clutch rollers 110 and stores power in the springs which propel the plungers 103 outwardly.

The release shaft 30 is normally held in its locked position by a detent or dog 140 (Fig. 12), freely mounted on a shaft 141. A stud 142 on a trip arm 143 mounted on, and to turn independently of, the release shaft 30, contacts the end of the dog 140, the trip arm 143 being spring-pressed in counter-cloclnvise direction by a spring 144 (Fi 11) to maintain such contact. The spring 144 is guided at its lower end by a pilot 145 on a link 146, and at its upper end, by two identical spring pilots 147 pivoted on a stud 148 on the end of an arm 149, secured to the release shaft 30. An arm 150 (Fig. 12) is also fast on the release shaft 30, and has a stud 151 pressed against the under side of a finger 152 on. a hub 153. The arm 143 is also on the hub 153; the hub 153, arm 143, and finger 152 forming a single element.

As fully explained in the Shipley Patent,

No. 1,619,796, depression of a release key 154 withdraws the retaining dog 140 from the path of the stud 142 to release the machine. This is accomplished by a pin 155 traversing the cam slot 156, in a release bar 157, upon depression of the key 154. The release bar 157 is supported at its lower end by a link, (not shown, but fully described in the Shipley patent mentioned), and at its upper end by a link 158, pivoted on a key frame (not shown). The link 158 has an extension provided with a stud 159 projecting into a notch 160 in an arm 161 pivoted on the shaft 141 and connected with the dog by a yoke 162.

Depression of the release key 154, through pin traversing the cam slot 156, shifts the release bar 157 downwardly to rock the link 158 counter-clockwise. The link 158, through pin 159, rocks arm 161, and by the yoke 162 withdraws the retaining dog 1 40 out of the path of the stud 142, to free the trip arm 143 to the action of the spring 144 11). Upon the withdrawal of the dog 140 from the path of the stud 142, the spring 144 expands and rocks an arm 149 clockwise (Fig. 11) to rock the release shaft 30 likewise. Clockwise movement of the release shaft 30 (Fig. 11), or counterrclockwise as viewed in Fig. 12, rocks the arm 150 and, by the pin 151, and finger 152, rocks the hub 153 clockwise to shift the stud 142 beneath the dog 140 where it remains until the machine completes its operation.

The releasing movement of the release shaft 30 moves thestud 148 (Fig. 11) on the arm 149, into the upper end 163 of a slot 164 in the link 146.

To restore the release shaft 30 to its normal locked position, a cam race 165, out into the side of a gear 166, pivoted at 167, on the side frame 168 of the machine, is provided. Entered in the cam race is a stud 169 on a restoring lever 170, pivoted at 171 on the side frame 168. A stud 17 2 on the free end of said lever projects into a notch 173 cut in the wall of an opening 174 in the link 146. The gear 166 receives one-half a rotation for each adding operation of the machine, as is well known in the art, from a gear 183 meshing therewith, and which gear is secured to the cam shaft 116, (see also Fig. 3). The cam shaft 116 receives one complete rotation for each operation of the machine, and the ratio between gears 183 and 166 is such that the latter receives one-half rotation for each rotation of the former.

The race 165 is provided with two cams V 175, which, during alternate operations of the machine, rock the restoring lever 17 0 clockwise, to lower the link" 146. A stud 184 on a pitman 185 uides the link in its downward movement. is above mentioned, upon release of the machine, the stud 148 is moved into the upper end 163 ofthe slot 164, and

therefore, the arm 1 29 and release shaft "30 are returned toward their normal positions immediately upon the downward movement of the link 146. This restoring movement of the release shaft 30 rocks the 150 clockwise (Fig. 13) to wipe the stud 1, 1 across the face 176 of a trip arm restoring lever 177, pivoted on shaft 141, to rock the restoring lever 177 clockwise. An edge 178 on the re.- storing lever 177 bearing against the lower side ofthe stud 142, rocks the trip arm 1 43, hub 153 and finger 152 clockwise to with draw the stud 142 from beneath he dog 140. The restoringmovement transmitted to the arm 123 is great enough to move the stud 142 past its normal position, and when in such osition east normal a s )llIl 179 connected P l 7 l 3 to the stud 180 on the retaining dog 140., and v to a stud 181 on a non-repeat detent 182, returns the retaining dog to its locking position in the path of the stud 142, and the of the race 165 returns the release shaft restoring lever 17 O to its normal position, and the stud 142 moves against the end of the dog 140, where it remains until the subsequent depression of a release key 154.

I The non-repeat detent 182 is provided to prevent a successive operation of themachine by maintaining the release key depressed during the entire operation of the machine. If the release key 154 is held depressed, the retaining dog 140 is held in its elevated position the end of the operation of the ma chine, and therefore, when the trip arm 143 and stud 142 are moved past their normal rpomachine. l Vhen the operator removes his fin.-

ger from the depressed key 154, the dog 140 is restored to its normal position, and in doing so, strikes the upper side of the non-repeat detent 182 and restores the non-repeat detent 182 to its normal position.

lVhenthe shaft 30 is released by the above described mechanism, it is rocked counterclockwise (Fig. 3) to disengage the restraining arm 31, secured thereto, from beneath the stud 32 on the clutch detent arm 33. lVhen the restraining arm 31 is disengaged from the stud 32, the spring 35 disengages the detent 36 from the abutment 37, on the switch controlling disk 38, and from the shoulders 39 and 40 (Figs. 3 and 4) of the tensioning and clutch release disks 41 and 42, respectively.

The clutch release disk 42, when freedby the clutch detent 36, enables the springpressed plungers 103 of the driven clutch member 46 to advance the loose rollers 110 up the inclined bottoms of the recesses 111 in the driven clutch member 46 until the rollers are pinched between such inclinedsurfa-ces and the encircling shell 88 o the drive member 88 of the clutch, which immediately grips the driven member 46 to turn the latter and the drive pinion 112 fast therewith.

Switch mechanism 3) out of the recess, in which outer position it is held by the unmutilated periphery of the I cam disk 38.

Near the end of the operation of the machine, the clutch detent 36 first arrests the switch controlling cam disk 38 with a recess 47 opposite a projection or stud 48 on one arm of a switch-operating lever 49, pivoted at 50 on the side frame 99 of the machine. The slight advance permitted the tensioning cam disk 41 subsequently to the arrest of the switch-controlling cam disk 38, brings the reduced periphery of the disk 41 into registry with the recess 47 of the switch controlling cam disk 38 to form a seat for the projec tion 48.

'Such advance of the tensioning cam disk 41 with its stud 43 relatively to the switch-controlling cam disk 38 defined by the slot in the disk 38, also results in tensioning the spring 44, and the projection 48 when it enters its seat formed by the recess 47 of the switch-controlling disk 38 and the reduced periphery of the tensioning disk 41, looks the latter against reverse rotation and holds the spring 44 under tension.

The opposite arm of the switch operating lever 49 is hooked to take over a stud or projection 51 on a projecting toe formed on one arm of a switch control lever 52 (Figs. 1, 2, 3, 7, 8 and 9) pivoted at 53 to ears 72 (Figs. 1 and 7 The arm 52 is pivoted on a stud 53 carried by a lug on a horizontal bracket 54 supported on the frame of the motor 80. The lever 52 is provided with a lip 55 which normally engages a flange 56 (Figs. 1,2,7, 8 and 9) on a slide 57. The slide 57 is slotted at its left hand end (Figs. 1, 2, 9 and 10) to embrace a stud 58 upon which itis also adapted to pivot. At its right end. the flange 56 has secured thereto an insulating block 75 which rests upon switch blades 76 mounted at their opposite ends on an insulating block carried by the bracket 54 near one end, as shown in Figs. 1, 2, 8 and 9. These switch blades 76 are resilient, as is customary, to normally spring away from their companion contacts 79 mounted on a block of insulation carried at the opposite end of the bracket 54. Pivoted to the slide 57 011 a stud 70 is a pawl (Fig. 10) having a cam slot 66 near the left hand end thereof, through which projects a stud 67, mounted.

on the switch-control lever 52. A spring 68,

stretched between a stud on the pawl 65 and a stud on the slide 57, holds the lower edge 124 of the cam slot 66 in contact with the stud 67. A spring 69 stretched between a. stud on the switch-control lever 52 and a stud on the bracket 54, normally tends to rock the lever 52, slide 57 and pawl 65 upwardly as a unit about the pivot 53 to relieve the pressure of the slide on the blades 76, as shown in Figs. 1 and 2, and allow them to disengage from their contacts 79. The switch blades are. limited in their disengaging movement by a bracket 77 which is provided with a block of insulation 78.

Returning to the clutch mechanism (Fig. 3), the spring 69 operates through the switch control lever 52 and its stud 51 to maintain the latter pressed against the hooked end of the switch-operating lever 49, and it is the tension of this spring exerted through lever 52 which rocks the lever 49 counter-clockwise to seat the projection 48 thereof in the recess 47 of the switch controlling cam 38 and the reduced periphery of the spring-tensioning cam 41.

When the machine is released for operation by withdrawal of the clutch detent 36 from the shoulders 39 and 40 on the clutch release disk 42, and the tensioning disk 41, respectively, as well as from the path of the abutment 37 on the switch-controlling cam 38, the spring 44 sharply advances the switch-control cam 38 to rock the switch operatinglever 49 clockwise. The hooked arm of the switchoperating lever 49 embracing the projection 51 on the switch control lever 52, draws the latter in clockwise direction against the tension of the restoring spring 69.

The lip 55 of the switch-operating lever 52 normally overlies the flange 56 of the slide 57 which lip carries the insulated contact block 75 resting on the switch blades 76.

When the lever 52 (Fig. 3) is rotated clockwise, as above described, it causes the switch blades 76 to contact with the terminals 79 carried by the bracket 54, to close a circuit through the motor 80 (Fig. 1). When the driving motor 80 operates after the circuit has been closed, as above described, its armature shaft 85 (Figs. 6 and 9) rotates, and its worm 86 rotates the worm gear 87 which is loosely mounted on the hub of the clutch shell 88 secured to the drive shaft 89.

Secured to the worm gear 87 is a hollow drum 90. Loosely mounted on the shaft 89 is a pawl-carrying disk 91 (Figs. 5 and 6). A clock spring 92 is mounted on the hub of the disk 91, one end 93 of which spring projects into a hole in the drum 90. The other end 94 of the spring 92 projects into a notch out into the hub of the pawl-carrying disk 91. Mounted on the disk 91 are two pawls 95. Secured to the shaft 89, in the plane of the pawls 95, is a ratchet disk 96 having a notch 97 for each of the pawls 95. Springs 98 are adapted to hold the pawls in engagement with the notches 97 when the mechanism is in the normal position and when the machine is operating. Loosely mounted on the hub of the ratchet disk 96 is a release disk 105 provided with cam slots 106. Mounted on each of the pawls 95 is a roller 107, each of which projects into one of the cam slots 106. The periphery of the release disk 105 is provided with notches 108 which receive lugs 109 formed on the outer edge of the flange of the drum 90. These lugs are provided for properly tensioning the spring 92. By disengaging the release disk 105 from the lugs 109 of the drum, and rotating it in a clockwise direction, the pawl-carrying a clockwise direction, thereby winding the spring 92. When the proper tension has been obtained, the lugs 108 of the release disk 105 are again engaged with the notches 109 of the drum 90.

When the worm gear 87 (Fig. 6) is rotated by the armature shaft 85, as above described, the drum 90 is rotated, and with it the spring 92. The spring 92 (Fig. 5) as above described is attached to the pawl-carrying disk 91 by its end 94, and therefore, this disk is also rotated with the drum 90. The pawl-carrying disk 91 rotates the release disk 96, through the pawls 95, which are mounted on the disk 91 and the disk 96 rotates the shaft 89 to be rotated, thereby rotating the clutch shell 88 secured thereto. lVhen the clutch detent 36 releases clutch disk 42, as above described, the clutch rollers 110, (Fig. 4) mounted on the clutch disk 42 become wedged between the inclined surfaces 111 of the driven clutch member 46 and the-inner wall of the clutch shell 88, to rotate the member 46 and shell 88 together.

The clutch member 46 turns a driving pinion 112 (Figs. 3 and 6) which meshes with an intermediate gear 113 (Fig. 3) mounted on a stud 114. The gear 113 meshes with a gear 115 secured to the main cam shaft 116 of the machine. From this it can be seen that when the worm gear 87 is rotated by the motor, it drives the shaft 89 through the drum 90, clock spring 92, disk 91, pawls 95 and disk 96. Ho tation of the shaft 89 rotates the clutch shell 88 therewith, which in turn, is clutched to the driving pinion 112 by means of the rollers 110 and clutch member 46.

If an interference occurs in the mechanism during a cycle of operation, the main cam shaft 116 suddenly stopped. This prevents rotation of the gears 115 and 113 and pinion 112, thereby preventing rotation of the drive shaft 89 and the ratchet disk 96. However, the worm gear 87 can continue to rotate be cause the spring 92 is interposed between the drum 90 and the ratchet disk 96. Continued disk 91 is rotated in.

rotation of the drum 90 winds up the spring 92. Since the ratchet disk 96 is held against movement, the pawls 95 are also held against movement. However, the release disk 105,.

which is connected to the drum 90 by means of the notches 108 and. lugs 109, continues to rotate with said drum. The shape of the cam slots 106 (Figs. 2 and 5) is such that as the release disk 105 rotates, the cam-shaped walls 120 of the slots 106 cam the rollers 107 outwardly and away from the driveshaft 89 to disengage the pawls 95 from the shoulders 97 0 said pawls and the pawl-carrying disk 91, to. rotate with the drum 90. This disconnects the driving motor 80' from the driving'oanr shaftv 116 thereby preventing strain on, or shearing'of, some of the parts.

Continued rotation of the worm 86 and worm gear 87 rotates the drum 90, and release.

plate 105 and tensions the. spring 92. The: pawls 95 mounted on the carrier disk 9L travel with the release plate.

Obviously long-continued rotation of the worm 86 would eventually wind the drive spring 92 so tightly that it would serve as a rigid connection, to prevent which disadvantage, means is provided to. trip the switch mechanism to interrupt: the flow of current to the motor 80. To this end I provide the pawl pivoted intermediate its ends at 7 0' to the slide 57. The camslot. 66 in. one arm of the pawl embraces the laterally extending stud 67 projecting from one arm of the switch operating lever 52,. the. flange 55 of which it will be remembered, normally lies over the flange 56 of the slide and carries a. block of. insulation resting on the switch blades 76'. The free hooked end 81 of the pawl 65 normally extends over and is disconnected from a lug 82 extending laterally from an arm 83 fast on a stub shaft 84 suitably jfournaled in the motor frame. The free. end of an arm 121 (Figs. 1, 2 and 9)- also fast on the stub shaft 84 extends over the outer face of'the tensioning plate 105 and lies in proximity to the outer ends of the cam slots 106 therein, as the plate 105 and drum rotate. A rin 122 draws the arms 121 and 83 to the left Fig; 1)., a limit pin 126 in the arm. 121 contacting the edge of a bracket 127 forming part of the motor frame, to limit the movement of the arms 121 and 83 in counter-clockwise direction, so that the lug 82 of the arm 83' lies be hind and. beneathv the hook. 81 of the pawl 65. When the switch is closed by the operation of the hooked arm of the switch-operating lever 49 (Fig. 3) in clockwise directionupon the switch control lever 52, the pawl 65 swings downwardly into contact with the lug 82 of the arm 83, with its hook 8-1 engaged with the lug, and upon the release of the switch mecha nism, and the consequent breaking of 13116611 cuit at the end of an operation of the-machine,

the pawl 65 returns to its ineffective position.

the ratchet disk 96, thereby permitting ing the next succeeding operation.

' But when, for some cause, the machine stops intermediate the beginning and end of an operation, and the drive pawls 95 (Fig. 5,) are disengaged from the drive ratchet 96 by the advance of the releasing disk 105 with its cam slots 106 relatively to the rollers 107, the rollers are brought into a path which will cause them to wipe against the edge of the trip arm 121.

Now as the drum 90 rotates, one of the rollers107 engages a surface 123 on the arm 121, to rock the shaft 84 to rock in a clockwise direction. At this time the hook 81 is engaged with the lug 82 of the arm 83, as shown in'Fig. 7 Rocking of the shaft 84 rocks the arm 83 secured thereto in a clockwise direction, thereby drawing the pawl 65 and the slide 57 toward the right until the flange 56 thereon is moved from beneath the lip 55 of the switch-contro1 lever 52, as shown in Fig. 2. The movement of the flange 56 from beneath the lip 55 permits the switch blades 76 to move upwardly away from the terminals 79, thereby cutting off the current through the driving motor 80 and stopping the motor.

The slot 66 in the pawl 65 (Fig. 10) is provided with a cam surface 124i adapted to cause the pawl 65 to rock upwardly after the arm 83 has been rocked far enough to move the flange 56 from beneath the lip 55, thus positively moving the hook 81 from the lug 82 and permitting the spring 69 to move the pawl 65. into the position shown in Fig. 2.

From the" above description it is apparent that should an interference occur in the mechanism, the driving mechanism will-be cushioned by the spring 92, the winding up of which will control mechanism which, in turn, will cause the motor to be disconnected from the driving shaft'89 and the current through the driving motor to venting any damage to the parts. In machines of the type to which this invention is shown attached, the load on the main operating shaft varies during the operation of the machine, as the various parts of the machine perform their functions. The spring 92 also provides a means for cushioning the driving mechanism when the load on the main operating shaft is suddenly increased during the operation of the machine.

A dial 117 (Fig. 3) secured to the main cam shaft 116 (Figs. 1 and 3) of the machine is provided to enable the mechanic or operator to determine at what stage in the cycle of operation the interference occurred, and from this, be able to determine the probable cause. A fixed pointer 118 cooperates with the dial.

After the cause of the interference has been discovered, and corrected, it is desired to return the mechanism to its normal or home position, so that it will properly function durbe cut off, thereby pre-' This is I usually accomplished by a handle, by means of which the main cam shaft 116 is rotated and brought home. As the mechanism reaches its home position, a stud 130 carried by the gear 113 (Fig. engages the lower end of a link 131 suspended from the arm 33 of the clutch detent 36, thereby raising the arm 33 to position the stud 32 above the path of the clutch detent tripping arm 31, where upon the arm 31 is returned by springs (not shown) to its normal position beneath the stud 32. Raising the arm 33 rocks the detent 36 in a clockwise direction into the path of the abutment 37 on the switch-controlling cam disk 38 and shoulders 39 and 40 on the tension cam disk 41 and the cam disk 42, respectively. Engagement of the detent 36 with the abutment 37 holds the switch-controlling cam disk 38, thereby permitting the roller 18 to again drop into its seat formed by the recess 47 in the control disk 38 and the reduced periphery of the disk 42, and permitting the lever 49 to be rocked in a counter-clockwise direction. This movement of the lever l9 is effected by the spring 69 (Figs. 2, 7, 9 and 10) which. rotates the switch control lever 52 upwardly. A spring 125 (Fig. 9), stretched between a stud on the slide 57 and a stud on the switch control lever 52, thereupon moves the slide 57 toward the left to again position the flange 56 beneath the lip 55. The parts are now in their normal positions, and the mechanism can again be released for operation, as above described.

The armature shaft 85 (Figs. 6 and 9) of the motor might stop in -any position, and therefore, it is possible that one of the rollers 107 will stop in such a position that it will hold the trip arm 121 in its moved position, thereby holding the arm 83 and its lug 82 in the path of the hook 81, as shown in Fig. 2. For'this reason the pawl 65 is mounted to rotate on its stud 70, so that if this condition should exist, and the operator should attempt to start the machine, the hook 81 is broughtdown on the top of the lug 82. The slot 66 is large enough to permit the pawl 65 to rotate on its stud 70, if the lug 82 is in the path of the hook'81. This permits the slide 57 to be rotated on the pivot 58 to move the blades 7 6 into contact with the terminal 79 to close the switch. lVhen the motor is. then started, and the worm gear 87 rotates the drum 90, and, through the spring 92, causes the pawl-carrying disk 91 together with the pawls 95, to be rotated, the roller 107 is moved away from the arm 121 to permit the spring 122 to rock the arms 83 and 121 in a counter-clockwise direction to move the lug 82 from beneath the hook 81, and permit the spring 68 to rock the pawl 65 to engage the hook with the back of the flange 82 in the manner above described and as shown in Fig. 7.

\Vhile the form of mechanism herein shown and described is admirably adapted to fulfill the objects primarily stated, it is to be understood that it is not intended to confine the invention or the one form of embodiment herein disclosed, for it is susceptible of embodiment in various forms, all coming within the scope of the claims whichfollow.

What is claimed is:

l. The combination of a main operating shaft, an electric motor for driving said shaft, an inherently resilient driving connection be tween said motor and said shaft to transmit power from the motor to the shaft, coupling means between said resilient driving connection and said operating shaft, and means for automatically rendering said coupling means ineffective when said shaft is arrested prior to the completion of its operation, thereby disconnecting said motor from said shaft.

2. The combination of a main operating shaft, an electric motor for driving said shaft, an inherently resilient driving connection between said motor and said shaft to transmitpower from the motor to the shaft, coupling means between said resilient driving connection and said operating shaft, a switch for closing a circuit through said motor, additional means driven by the motor to auto matically render said coupling means ineffective; and means rendered effective by said additional means, to open said switch when said operating shaft is arrested prior to the completion of its operation, thereby disconnecting said motor from said operating shaft and simultaneously interrupting the flow of current to said motor.

3. The combination of a main operating shaft, an electric motor for driving said shaft, a resilient driving connection between said motor and said shaft to transmit power from the motor to the shaft, coupling means between said resilient driving connection and said operating shaft, means to positively and automatically unco-uple said coupling means when said shaft is arrested prior to the completion of an operation, thereby disconnecting said motor from said shaft, a switch for closing a circuit through said motor, and means rendered effective by the uncoupling means to automatically open said switch when said coupling means becomes ineffec tive.

4. The combination of main operating shaft, an electric motor for driving said sh aft, a resilient driving connection between said motor and said shaft, a coupling member secured to said shaft, coupling shoulders on said member means directly connected to said resilient means, coupling pawls on said means adapted to cooperate with said coupling shoulders, and means for causing said pawls to be disconnected from said coupling shoulders when said shaft is arrested.

5. The combination of a main operating shaft, an electric motor for driving said shaft, a resilient driving connection between said motor and said shaft, a coupling member secured to said shaft, coupling shoulders on said member, pawl-carrying means directly connected to said resilient driving connection, coupling pawls on said pawl-carrying means adapted to cooperate with said coupling shoulders, means for causing said pawls to be disconnected from said coupling shoulders when said shaft is arrested, a switch to control a circuit through said motor, and means for automatically opening said switch after said coupling pawls have become disengaged from said shoulders.

6. The combination of a main operating shaft, an electric motor for driving said shaft, a switch for closing a circuit through said motor, coupling means for coupling said motor to said shaft, means for closing said switch, cams for uncoupling said coupling means when said shaft is arrested, and means for rendering said means for closing said switch ineffective, and operated by said coupling means only when said coupling means is ineffective.

7. The combination of a main operating shaft, an electric motor for driving said shaft, a switch in circuit with said motor, a. switch controlling lever to close said switch, a slidable member mounted on said lever, and means controlled by said main operating shaft to shift said slidable member relatively to the switch controlling lever, to render the lever ineffective, and enable said switch to open.

8. The combination of a main operating shaft, an electric motor for driving said shaft, a switch in circuit with. said motor, a switchcontrolling lever to close said switch, aslid able member mounted on said switch-controlling lever, coupling means for coupling said motor to said operating 'sha t, cams for causing said coupling means to be rendered ineffective when said shaft is arrested, and means operated by the coupling means, when in its inoperative position, to shift said slidable member on said switch-controlling lever to render said lever ineffective, and enable said switch to open.

9. The combination of a main operating shaft,an electric motor for driving said shaft, a switch in circuit with said motor, a switchcontrolling lever to close said switch, a slidable member mounted on said switch-controlling lever, coupling means for coupling said. motor to said operating shaft, cams for causing said coupling means to be rendered ineffective when said shaft is arrested, means for moving said sliding member to enable said switch to open, and a pawl for connecting said last-mentioned means to said slidable member.

10. The combination of a main operating shaft, an electric motor for driving said shaft, a switch in circuit with said motor, a switchcontrolling lever to close said switch, a slid- BBQ loo

able member mounted on said switch controlling lever, coupling means for coupling said motor to said operating shaft, cams for causing said coupling means to be remlered ineffective when said shaft is arrested, means for moving said sliding member to enable said switch to open, a pawl for connecting said last-mentioned means to said slidable member, and a cam on said pawl for causing it to be disconnected from said means when said switch has opened.

11; In a machine of the class described, the combination with a motor; a drive shaft; and a driven shaft; of an inherently resilient power transmitting driving connection between said shafts; a driven coupling member secured to said driven shaft; a driving coupling means cooperating with said driven coupling member, the resilient power transmitting connection being attached to the driving coupling means and to the motor; and means operated directly from the motor to render the coupling means ineffective as to coupling, when said driven shaft is arrested prior to completing its operation.

12. In a machine of the class described, the combination of a drive shaft; a driven shaft; a resilient power transmitting driving connection intermediate said releasably engage said disk; means carrying said pawls, one end of the resilient driving connection connected to the pawl carrying means; rotatable means connected to the opposite end of the resilient driving connection, and to the drive shaft; and means supported by said rotatable means for rendering said coupling pawls ineffective when the driven shaft is arrested prior to completing its operation.

13. In a machine of the class described, the combination of a drive shaft; a driven shaft; a spring driving connection to transmit power from the drive shaft to the driven shaft; rotatable means connected to the drive shaft and to one end of the spring; a coupling member mounted on the driven shaft; a rotatable disk connected to the opposite end of the spring, and carrying pawls to releasably engage said coupling member; and means carried by said first-named rotatable means and having cam slots to render said pawls ineffective at certain times.

14. In a motor drive, the combination with a main operating shaft; and a driving motor; of a driving connection between the motor and the main operating shaft, including a coupling comprising a drive and a driven member; and an inherently resilient powertransmitting member connected with the motor and with the drive member, respectively, to transmit power from the motor to the drive member; a switch to control the supply of power to the motor; and means operable by the coupling to open the switch.

shafts; a coupling disk on the driven shaft; coupling pawls to 15. In a machine of the class described, the combination with a main operating shaft; a driven member; a motor; and a clutch mechanism interposed betweenthe motor and the main operating shaft; of an elastic drive i11- terposed between the motor and the driven member, the elastic drive including an inherently resilient means driven by the motor; drive and driven coupling members, the resilient means secured to the driving coupling member to transmit power from the motor thereto; the driven coupling member connected to the first-mentioned driven member; and releasing means operable by the motor to disconnect the coupling members while the clutch mechanism remains effective.

16. In a machine of the class described, the combination with a main operating shaft; a driven member; a motor; and a clutch mechanism interposed between the motor and the main operating shaft; of an elastic drive interposed between the motor and the driven member, the elastic drive including an inherently resilient means driven by the motor; a ratchet member connected to the driven member; a pawl member to which the resilient means is connected, to coact with the ratchet member; and a releasing cam operable by the motor to disengage the pawl member from its ratchet member in case the drive on member is arrested prior to completing an operation, while the clutch mechanism remains effective.

17. In a machine of the class described, the combination with a main operating shaft; a driven member; a motor; and a clutch mechanism interposed between the motor and the main operating shaft; of an elastic drive in-v terposed between the motor and the driven member, the elastic drive including an in herently resilient means driven by the motor; a ratchet member connected to the driven member; a pawl carrier ournaled on the driven member,"the resilient means connected to the pawl carrier to turn the latter; a pawl on the pawl carrier to connect the carrier and the ratchet; a releasing disk rotatable with the resilient means and having a cam slot to engage the pawl'and disconnect it from its ratchet while the clutch mechanism remains effective.

18. In a machine of the class described, the combination with a motor; a clutch mechanism comprising drive and driven members; and means to connect and disconnect the clutch members, including a clutch-d'etent; of a coupling interposed between the motor and the drive member of the coupling, and including a driven member and a drive member; an inherently resilient power-transmitting element connected with the motor and with the drive member of the coupling, respectively; and normally idle means operated from the motor and rendered automatically effective by the arrest of the clutch mechanism prior to the completion of its operation to uncouple the drive and driven members of the coupling.

19. In a machine of the class described, the combination with a motor; a clutch mechanism comprising drive and driven members; and means to connect and disconnect the clutch members, including a clutch-detent; of a coupling interposed between the motor and the drive member of the coupling, and including a driven member and a drive member; and normally idle means operated from the motor and rendered automatically effective by the arrest of the clutch mechanism prior to the completion of its operation to uncouple the drive and driven members of the coupling.

20. In a machine of the class described, the combination with a main operating shaft; a driven member; a motor; a switch to control the supply of power to the motor; and a clutch mechanism interposed between the driven member and the main operating shaft of an elastic drive located between the motor and the driven member, including a resilient driving element actuated by the motor; separable coupling members connected with the resilient driving element and with the driven member, respectively; means to effect the disconnection of the separable coupling members while the clutch mechanism remains effective; clutch-controlled means to close and open the switch; and means rendered effective by the disconnection of the separable coupling members to disable the switch-closing means and enable the switch to open.

21. In a machine of the class described, the combination with a main operating shaft; a driven member; a motor; a switch to control the supply of power to the motor; and a clutch mechanism interposed between the driven member and the main operating shaft of an elastic drive located between the motor and the driven member, including a resilient driving element actuated by the motor; separable coupling members connected with the resilient driving element and with the driven member, respectively; means to effect the disconnection of the separable coupling members while the clutch mechanism remains effective; clutch-controlled means to close and open the switch, including a shiftable member having an insulated contact; a normally idle actuator to move the shiftable member in one direction to release it from the clutch controlled means; and means controlled by the arrest of the driven member prior to the completion of its operation to drive the actuator.

22. In a machine of the class described, the combination with a main operating shaft; a driven member; a motor; a switch to control the supply of power to the motor; and a clutch mechanism interposed between the driven member and the main operating shaft; of an elastic drive located between the motor and the driven member, including a resilient driving element actuated by the motor; separable coupling members connected with the resilient driving element and with the driven member, respectively; means to effect the disconnection of the separable coupling members while the, clutch mechanism remains effective; clutchcontrolled means to close and open the switch, including a member shiftable in one plane of travel to close the switch and enable it to open, and in another plane to release itself from the control of the clutch; a normally idle actuator to move the shiftable member to release it from the control of the clutch; and means rendered effective upon the arrest of the driven member prior to the completion of its operation, to drive the actuator.

23. In a machine of the class described, the combination with a main operating shaft; a driven member; a motor; a switch to control the supply of power to the motor; and a clutch mechanism interposed between the driven member and the main operating shaft; of an elastic drive located between the motor and the driven member, including a resilient driving element actuated by the motor; separable coupling members connected with the resilient driving element and with the driven member, respectively; means to effect the disconnection of the separable coupling members while the clutch mechanism remains effective; clutch-controlled means to close and open the switch, including a-shiftable memher; a latch member pivotally mounted on the shiftable member; an actuator engaged by the latch member when the switch is closed; and means rendered effective upon the arrest of the driven member prior to the completion of its operation, to drive the actuator and cause it to release the shiftable member from the control of the clutch.

24. In a machine of the class described, the combination with an intermittently operable clutch mechanism, including a drive and a driven member; and means to effect the connection and disconnection of the clutch members; a motor; and a switch in circuit with the motor to control the supply of power thereto; clutch-controlled means operable to close the switch and enable it to open, including a control member operable in two different planes of movement; a coupling interposed between the motor and the drive member of the clutch to automatically uncouple upon the arrest of the driven member of the clutch intermediate the beginning and end of any of its operations; and means rendered effective by the uncoupling of the coupling, to shift the switch control member to ineffective position, to enable the switch to open. 7

In testimony whereof I and my signature.

WILLIAM H. ROBERTSON. 

